Field
The present disclosure relates generally to an interface between a host processor and a peripheral device and, more particularly, to an interface and dynamically adjustable shared bus connecting both next-generation and legacy sensors and accommodating multiple modes of operation.
Background
Manufacturers of mobile devices, such as cellular phones, may obtain components of the mobile devices from various sources, including different manufacturers. For example, an application processor in a mobile computing device may be obtained from a first manufacturer, while sensors employed by the mobile computing device may be obtained from one or more other manufacturers. Various standards-based or proprietary interfaces have been defined, typically directed to a specific application or type of application. For example, cellular telephones may use a communications interface that is compatible with or conforms to an Inter-Integrated Circuit (I2C) compatible bus standard specified by the Mobile Industry Processor Interface Alliance (MIPI).
The I2C interface has become a widely adopted communication interface that may be optimized for specific applications. For example, the MIPI standards define a camera control interface (CCI) that uses a two-wire, bi-directional, half duplex, serial interface configured as a bus connecting a master and one or more slaves. Thus, the CCI protocol uses the I2C Serial Clock (SCL) and Serial Data (SDA) lines, and CCI devices and I2C devices can be deployed on the same bus such that two or more CCI devices may communicate using CCI protocols, while any communication involving an I2C bus uses I2C protocols. Later versions of CCI can provide higher throughputs using modified protocols to support faster signaling rates. Similarly, I2C may be implemented for sensor interfaces. However, the advent of new sensors, together with a need for backward compatibility to support legacy sensors and power savings for “always-on” type applications, requires high data rate throughputs that are beyond the capability of legacy I2C. Some sensors examples that are targeted for such higher throughput speeds are aggregated sensors, sensors hubs, touch sensors, low definition camera sensors, etc. However, the challenge remains of how to provide higher throughputs for next-generation sensor devices while concurrently accommodating operation of legacy sensor devices on the same bus.
There exists an ongoing need for providing optimized communications on serial interfaces configured as a bus connecting different types of peripherals or cooperating devices to a processor.